Railway traffic controlling apparatus



July 20, 1943. R. A. M'JCANN RAILWAY TRAFFIC CONTROLLING APPARATUS FiledSept. 3. 1942 l/VVE/VIUIZ fiozzaZc/A 1110001212 2.

HISATIQZVEK wi h v m B E i ENE U U U fi n $3 m mww d NAN 2 Nmd 5m m5 mwas QQQ 5E T w 5 T 7 M Patented July 20, 1943 ItAiLWAY TRAFFICCQNTBOLIJNG Y APPARATUS V Bohemia A. McCann, Swissyale, 2a.; assigpprtir' The Union Switch & Signal Company, Swiss- 7 vale, Pa., acorporation of Pennsylvania,

Apa a w Septembe 3, l 4 N9: 4 7 433 4 Claims.

My invention relates to railway traffic con trolling apparatus, and moreparticularly to train indication means for use in connection with entralized t-raific controlling systems for single a-ck railroads.

In systems of this character, it customary to divide the track intoblocks each extending from one p in siding t0 he next nd to satrainmovements through the blocks by means of an absolute permissive blocksystem which the signals are generally controlled over line circuits,the energization of which i dependent upon the positions of trains andtheir direction of movement, as reflected by track circuits, the headblock signals which govern traffic motor ments into the single trael;hlocks being also sub,- ject to manual control by means of a ico mmunifcation system of a sui able t pe. It is also the practice to provide anilluminated track diagramat the office for the uidance of {the operator,comprising aminiature representation of the com trolled stretch of trackhaving indication lamps mounted thereon at spaced points,the lamps beeing governed by means otthe communication system to indicate whentrainsare passing, the

corresponding trackway tations. Since these stations correspondgenerally to the locations from which OS reports of the assage of trainsare transmitted by wire by local operators in manual train dispatchingsystems, the lamps are commonly designated as OS lamps, and each iscontrolled in accordance with the icondition of a short 0S sectionincluding the track switch at the entrance .or exit end of the block.

In systems of lll1i5 .(;ha- I&Cter'it has been found desirable toindicate the presence of .a train whenever it may be in the controlledterritory, by the provision of ,one or more additional. lamps on thetrack diagram. These additional lamps.

block indication, indicating the presprovide a once of a train in thecontrolled territory at uch times as the OS indication lamps are notlighted, even though gthe territory is ,occupied, as, for example, whena the "08 section-at the entrance end or the block but has, not yetreached the corresponding 08" section at its exit end. One manner inwhich this has been accomplished has been by the provision of approachindications, to indicate when a train occupies one or th other of twoapproach zones, located within but adjacent to the ends of the block,the transmission ,of these,

indications by the communication system being effected by approachrelays con-trclled foyer ad ditional line wires its shown, for example,,in

train has passed out-of.

r ce t p actice is t Le ters Beteh or h ni States 1 2 8 ran ed De emberRai way traf ic c n l a c r i such approach relay are provided primarilyw ert -e th sw t h lockin h a a n is a proaching the exit end of ablock, and the more v omit the: approach control of the switch to reducethe cost of the system, particularly as installed on roads hayingrelatiyely light traffic. In suchsystemsay preach relays are notavailable, and in any case the use or approach relays to rovide a blockindication requires the approach to be extended so that they overlap, asexplained in the Allen patent, th s eeneranyr q irine the 11 13 3.lationof additional line wires." 7 The object of my intention is toprovide a bloc}; indication which correctly indicates the condition of asinglectreck block at all times through the medium of the existingcommunication s' stern and which does not requirethe installat on of anypecial apparatus whatever in tlie iel 9. term of pparatus embo y my mm:

bloc}: equipped with continuous track circuits, ac pre tia with a trac ly R h block extending pet-ween the ends of two passing sidingsidentified by the track switche I and 1.

Train rements through the hloclrare governed by a c ralized trai ficcontrol system, including an automatic clock signaling systern of theab: solute permissive controlled by the track relays together wi-thcentral off ce control of thecpposin head {clock signals, such es thesignals Rn?! L A8, by means of the signal control relays and mine, thelatter being go erncd. by leans of a suitable communication system froma central oihce shown diagrammatically in the lower portion of the view.The block signaling system as shown corresponds generally to thatdisclosed in Letters Patent of the United States No. 207 1517, granted Aril 20, 1937 to n. S. Young and It; A. McCann, for Railway tra'fliccontrolling apparatus. 7

As shown, the block is provided with only one s g a i c ntrolledautomatically by the.

21, 1937, to E. M..Allen, for 7 tion will now be descibed and the novelfeatures track relays TR of the track sections in advance thereof,through the medium of a line relay HR and a repeating relay HP, eachsuch relay being identified by a prefix corresponding to the signal itcontrols. Each intermediate signal has the usual directional stick relayS to provide for permissive following train movements. At each end ofthe block a time looking relay AS is provided, controlled by theassociated head block signals and signal control relay. Each relay AS isreleased when one of the associated signals is cleared, to open thecircuits for the opposing head clock signals, and to maintain them openin case the associated signal is manually put to stop, for apredetermined time interval measured by a time element relay TER.

The communication system connecting the central office with the variousstations comprising the head block signal locations may be of anysuitable type, but preferably is of the selective or code type, in whichcommunication is established intermittently between the control officeand various stations over a single pair of line wires, a suitable systembeing shown, for example, in the Letters Patent of the United States No.2,229,249, granted January 21, 1941, to L. V. Lewis, for Remote controlsystems. Direct wire control may also be used, and as illustrative ofeither form, direct wire connections are shown herein extending from oneterminal B of a suitable source of current over contacts of signallevers 236 and 88G at the ofiice through the signal control relays RZHSand LBHS in the field, to the other terminal of the same source, andlikewise over back contacts of the line relays R2HR and L8HR, associatedwith the head block signals, through the windings of correspondingindication relays RZHK and L8HK at the oflice, the latter relayscontrolling a block indication relay 2-8BK in accordance with myinvention. Similarly, back contacts of the track relays ITR and 'ITR forthe OS or detector track sections including the track switches I and 1control the indication relays ITK and 'ITK, and front contacts of theindication relays I'I'K, 'ITK and 2-8BK control corresponding lamps Emounted in the operators track diagram as shown.

The block signaling system operates in the manner described in the Youngand McCann patent hercinbefore referred to, the line relays HR for bothdirections being normally energized in tandem as shown, and the trackdiagram being normally dark.

It is believed that the apparatus of my invention may be readilyunderstood from a description of its operation, and accordingly it willbe assumed that with. the apparatus in the condition shown in thedrawings, the operator at the oflice moves lever ZSG to the right,thereby energizing the signal control relay RZHS with the object ofclearing signal RA2 for a train movement through the block from left toright. A circuit is thereby completed from one terminal B of a suitablelocal source of current over front contact ID of relay RZHR, normalcontact ll controlled by switch I, front contact l2 of relay RZHSthrough relay RA2HP to the other terminal C of the same source. RelayRA2HP therefore becomes energized to cause signal RA! to indicate clear,and by opening its back contact 13 opens the circuit for relay RZAS,which releases, and in turn opens contact H in the circuit for relay4HR. Relay 4HR therefore releases, causing the indication of theopposing intermediate signal 4 to change from caution to stop, and relay4HR opens contact IS in the circuit for the line relay for the nextsignal in the rear, in this case relay L8HR. Relay LBHR releases,closing its back contact l6, thereby energizing the office indicationrelay LBHK, and relay L8HK then closes contact 22 in the circuit forrelay 28BK; the latter relay, however, does not pick up at this time.

When the approaching train passes signal RA2 at clear to enter theswitch section at the entrance end of the block, the track relay ITR isreleased and by opening its contact l8 releases relay R2HR, the latterrelay in turn, by opening contact I0, releasing relay RAZHP to restoresignal RAZ to stop. The closing of back contacts i9 and I0,respectively, of relays ITR. and R2HR causes the energization of theindication relays ITK and R2HK, relay ITK closing its contacts 20 toeffect the lighting of the OS lamp IE, and relay RZHK closing contact 2|to complete the circuit for relay 28BK, which picks up, closing contact25 to light the block indication lamp l -8E.

The operator may now restore lever 25G to normal to release relay R2HSand thereby effect the reenergization of relay RZAS over its pick-upcircuit including back contacts 23 and 24 of relays R2HS and ITR as inthe system'of the Young and. McCann patent, thereby closing contact M inthe circuit for relay 4HR, but relay 4HR will remain deenergized by therelease of one or more of hte track relays ITR, 3TB, and HR as long asthe train occupies any one of these sections. Also relay L8HR will beheld deenergized by the release of one or more of the track relays 3TR,4TH, 5TB, GTR and 'IT'R as long as the train occupies any portion of theblock. Lamp IE will be extinguished by the release of relay I'IK whenrelay 1 TR is reenergized as the train vacates the OS section at theentrance end of the block, but lamp 28E will remain lighted until thetrain vacates the entire block, relay LBHK being held energized by relayL8HR, and holding relay 2-8BK energized over a stick circuit includingfront contacts 26 and I1 until after the last track relay 'ITR isreenergized.

It will be understood that as the train passes through the block, thedirectional stick relay 58 will become energized upon passing signal 5,and that relay RZHR will be reenergized when the track relay ETR picksup, by current of reverse polarity supplied from the negative terminal Nof a suitable source connected to the lower back contact of relay 5HP.Relay REHK will therefore release, but without affecting relay 2-8BK,which is now held energized over astick circuit which is independent ofrelay RZHK.

It will be readily apparent from the symmetry of the circuits that withthe apparatus in the normal condition, as shown, the movement of lever Gto the left will clear signal LAE, to allow a train moving from right toleft to'enter the block, and that the apparatus will then function in amanner similar to that described. The

block indication lamp 28E will be lighted by such train, the principaldifference being that" in this case relay 2-8BK will be held energizedover a stick circuit including contact 21 of relay RZHK in place ofcontact 26. Relay L8HK will release when the rear of the train signal 4and relay LBHR will become energized over a front contact of thedirectional stick relay AS.

The indication relays R2HK and LBHK replace the approach indicationrelays as used heretofore as, for example, in the above-mentioned Allenpatent, and it will be clear therefore that the object of my inventionis attained by the provision of but one additional relay, namely relay2--8BK, at the oflice, and without any additional apparatus in thefield.

Although I have hereinshown and described only one form of apparatusembodying my invention, it is understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination with a stretch of railway track comprising a singletrack block divided into track sections, a track relay for each tracksection, a line relay vfor each direction of traf ic through said block,means for energizing each line relay when all said track relays arepicked up and also when one or more of said track relays are released bya train moving in the corresponding direction at an intermediate pointin said block, a two position indication relay at a central oifice,means for operating said indication relay to one position upon therelease of both said line relays and to its other position upon theenergization of both said line relays,

and a block indicator controlled by said indio cation relay to indicatewhen it occupies said one position.

2. In combination with a stretch of railway track comprising a singletrack block divided into track sections each having a track relay, ahead block signal for each direction of traffic through said block, aline relay for, each signal, line circuits controlled by the trackrelays for energizing each line relay when the entire block isunoccupied and also when a train moving in a corresponding directionpasses an intermediate point in said stretch, means for manuallyclearing either signal eiiective only when its line re-' lay isenergized, to establish the direction for traflic movements through theblock, means responsive to the clearing of either signal to release theline relay for the other signal, a two position indication relay, meansfor operating said indication relay to one position in response to therelease of both said line relays and to its other position in responseto the energization of both said line relays, and a block indicatorcontrolled by said indication relay to indicate when it occupies saidone position.

3. In combination with a stretch of railway track compriisng a singletrack block divided into track sections each having a track relay, aline relay for each direction of traffic through said block, linecircuits controlled by the track relays for energizing each line relaywhen the entire block is unoccupied and also when a train moving in acorresponding direction passes an inter mediate point in said stretch, astick relay, a pick-up circuit for said stick relay including twocontacts in series, said contacts being both closed to complete thecircuit only when both line relays are released, a stick circuit forsaid stick relay including its own front contact and two contacts inmultiple, said last named contacts being both open only when both linerelays are picked up, and a block indication lamp controlled by acontact of said stick relay.

i. In combination with a stretch of railway track comprising a singletrack block divided into track sections each having a track relay, aline relay for each direction of traiiic through said block, linecircuits controlled by the tracl: relays for energizing each line relaywhen the entire block is unoccupied and also when a train moving in acorresponding direction passes an intermediate point in said stretch, anindication relay at a central office for each line relay, means forenergizing each indication relay when .the associated line relay isreleased, a stick relay, a pick-up circuit for the stick relay in-'cluding front contacts of both indication relays in series, a stickcircuit for the'stick relay including front contacts of both indicat onrelays in multiple, and a block indication lamp con- RONALD A. McoANN.

